U.S. Pat. No. 3,450,684 teaches the following reaction: ##STR2## where X is F, Cl, H, CF.sub.2 H, CF.sub.2 Cl or CF.sub.3 n is at least 1.
U.S. Pat. No. 3,560,568 teaches the following reaction: ##STR3## where X is F or CF.sub.3
U.S. Pat. No. 3,282,875 teaches that compounds represented by the general formula ##STR4## may be pyrolyzed at 200.degree.-600.degree. C. in the presence of a solid catalyst to compounds represented by the general formula ##STR5## where
M is a radical selected from the group consisting of F, OH, amino, OMe
Me is an alkali metal radical, or a quaternary ammonium radical
Z is F or OX
X is an alkali metal
X is F or CF.sub.3
n is 1 to 3
J. E. Fearn, et al teach in the Journal of Polymer Science, Vol. 4, Part A-1, p. 131-140, (1966) "Polymers and TerPolymers of Perfluoro-1,4,-pentadiene", that in the pyrolysis of the sodium salts of carboxylic acids which contain fluorine and chlorine in the beta position, sodium chloride is preferentially, but not exclusively eliminated. For example ##STR6##
U.S. Pat. No. 3,114,778 shows the pyrolysis of ##STR7## to a vinyl ether.
U.S. Pat. No. 4,138,426 shows the pyrolysis reaction ##STR8## where
Y is --COOR, --COOH, --COOM or --CN
R is an alkyl group of from 1-6 carbon atoms
M is an alkali metal
p is 1 to 5
n is 1 to 6
British Pat. No. 1,518,387 shows, and claims use of polymers from as membranes, compounds represented by the structure
CF.sub.2 .dbd.CFOCF.sub.2 (CFXOCF.sub.2).sub.l (CFX').sub.m (CF.sub.2 OCFX").sub.n --A where l is 0 to 3; m is 0 to 6; n is 0 to 4, and one of l and n is not 0; X,X' and X" are the same or different and respectively represent F or CF.sub.3 ; A represents --C.tbd.N, COF, COOH, COOR.sub.1, COOM and CONR.sub.2 R.sub.3 and R.sub.1 represents C.sub.1-10 alkyl group, R.sub.2 and R.sub.3 each represent a hydrogen atom or a C.sub.1-10 alkyl group and M represents an alkali metal or a quaternary ammonium group.
Compounds, such as ##STR9## are shown as prepared by the addition of two equivalents of hexafluoropropylene oxide to one equivalent of ##STR10## followed by decarboxylation to the vinyl ether. Compounds derived from the addition of one equivalent of the epoxide such as ##STR11## are excluded by the general structure shown above.
R. D. Chambers, in his book, Fluorine in Organic Chemistry, published by John Wiley & Sons, 1973, pages 211-212, teaches that carboxylic acid derivatives may be converted to olefins. The conversion is taught to involve the loss of carbon dioxide and formation of an intermediate carbanion. The intermediate then looses NaF to form the resulting olefin.